1. Field of the Invention
The present invention relates generally to biodegradable, recyclable packaging materials. More specifically, the present invention relates to packaging materials formed from cellulosic waste materials.
2. Description of the Prior Art
Packaging materials are widely used industrially and domestically to cushion products ranging from delicate equipment to office supplies to prevent damage to the products during shipment and handling. Suitable packaging materials are often composed of an expanded foam providing a low density, flexible packaging that protects a product from damage without adding significantly to the weight of the product when shipped. Although conventional expanded foam materials adequately cushion a product, disposal of the materials is difficult because they may not be biodegradable or recyclable.
Several problems are associated with conventional packaging materials, such as expanded polystyrene peanuts. Safety problems arise during manufacture because the peanuts are formed from styrene monomer which is hazardous to workers if inhaled or ingested. The packing peanuts also accumulate static charges that cause them to stick to a product when the peanuts are closely packed about the product within a shipping carton. Another disadvantage associated with the polystyrene peanuts arises when the packaged product is a breakable container filled with a solvent, solution or other liquid. If the container breaks during shipment or is not sealed properly, the liquid will leak throughout the shipping carton. Polystyrene peanuts do not absorb the liquid to minimize such leakage, and often shrink considerably when exposed to liquid, losing their cushioning effect. Furthermore, the nonbiodegradable peanuts are often discarded after use, adding to existing landfill waste disposal problems.
Expanded vermiculite is an alternative packaging material which is suitable for packaging glass containers filled with liquid because it is moisture absorbent. Vermiculite, however, includes fines which adhere to glass and plastic. The fines can contaminate solvents and damage electronic equipment when the fines remain on the products after being unpackaged. Although a product may be sealed with a packaging film, the fines often stick to the product as it is being removed from the film. Vermiculite is also environmentally harmful because it is not biodegradable and cannot be recycled.
Starch based formulations have also been used to prepare biodegradable packaging materials. Starch based peanuts, however, may also be unsuitable for packaging breakable containers because they may dissolve in the presence of liquid which may leak from the containers. Starch based products also tend to become tacky when exposed to conditions of high humidity which may exist upon shipping and handling of a product.
Recycled newspaper has been used to form a biodegradable, recyclable packaging material. These materials, formed from aqueous slurries of chopped newspapers, are molded into thin hollow walled shells or are extruded as pellets. Although these materials employ waste paper materials, they have several drawbacks. Such packaging materials do not have the cushioning properties and low density provided by expanded foam materials. The materials also require a significant amount of storage space before they are reused or transported for recycling.
There exists a need for a packaging peanut which overcomes the disadvantages associated with conventional packaging materials. The present invention provides such an improved packaging material.